Thousands of Iranians took to the streets Wednesday to mark the 30th anniversary of the 1979 seizure of the U.S. Embassy in Tehran, but the annual state-sponsored anti-American rally turned into another sign of the deep divisions persisting in this country.

As pro-government demonstrators ritually chanted "Death to America!" outside the former U.S. Embassy, opposition protesters used the occasion to vent their anger over a disputed presidential election in June and the harsh crackdown on subsequent protests. Converging on a square about half a mile from the former embassy, the opposition marchers denounced President Mahmoud Ahmadinejad with shouts of "Death to the dictator!"